A wireless device (e.g., a cellular phone or a smartphone) in a wireless communication system may transmit and receive data for two-way communication. The wireless device may include a transmitter for data transmission and a receiver for data reception. For data transmission, the transmitter may modulate a radio frequency (RF) carrier signal with data to generate a modulated RF signal, amplify the modulated RF signal to generate a transmit RF signal having the proper output power level, and transmit the transmit RF signal via an antenna to another device such as, for example, a base station. For data reception, the receiver may obtain a received RF signal via the antenna and may amplify and process the received RF signal to recover data sent by the other device.
Analog signals within the wireless device may undergo amplification during various processing operations. For example, an analog signal may be amplified when an RF signal is received from or transmitted to another wireless device. In some cases, an unwanted signal may also be amplified. For example, as the received RF signal is amplified, a second signal, that may be a blocker signal or jammer signal, may also be amplified and may interfere with data recovery. This interference may be associated with amplifier linearity. For example, when a strong blocker or jammer signal is processed by an amplifier with relatively low linearity, then the blocker and/or jammer signal may saturate the amplifier and the RF signal may not adequately and/or accurately be amplified. Blocker and jammer signal rejection may be improved with amplifiers having relatively high linearity.
Thus, there is a need to improve the amplification of analog signals by extending the linearity of amplifiers, and thereby improve the performance of the wireless device.